LSM1303 Animal Behaviour

“Wild male chimps that share meat with females double their chances of having sex with those females, a new study says” nationalgeographic.com

www.flickr.com

“Steps to Win a Girl’s Heart:

-          Prove that you really love her

-          Most girls like guys with confidence and courage

-          Care for her    “ wikiHow.com

See any similarities?

This goes to show that guys engaging in courtship for sex is purely an evolutionary trait passed down from our ape ancestors. So don’t blame them for being sexually rather than emotionally driven when it comes to love, blame it on our genes.

On a more serious note, this article does provide insights into aspects of chimpanzee behavior, in particular, the idea that hunting has an additional sexual motivation.

Meat is not only nutritionally important as a protein source for chimps, it is socially important as well. Meat is highly prized in their diet, and most of the time the males do the hunting. Furthermore, the killer usually has full rights to the meat. In this way, being able to kill and share meat with a female gives an indication of social stature and ability in the male. Since the social structure of chimps is based on hierarchy, males with more meat to share are more dominant when it comes to matings.

However, a study conducted by Mitani and Watts (2001) on chimps at Ngogo in Kibale National Park does not support the hypothesis that male chimps hunt solely to obtain meat that they swap for matings. It shows that the presence of oestrous females did not predict the tendency for chimps to hunt. Although several factors are likely to affect chimpanzee hunting decisions and meat sharing, the results indicate that primary causes will not be found through invoking simple reproductive considerations.

Reference

John C. Mitani and David P. Watts (2001). “Why chimpanzees hunt and share meat?” Animal Behaviour 61 pp. 915-924.

We balk when we hear of rape cases in the papers but somewhere in the world, someone is breeding an animal that commits rape. What amazed or rather disgusted me even more was that some of these people do it knowingly!

In the book, ‘Animals in Translation’ by Temple Grandin, she speaks of horse breeders who keep their stallions locked in their stalls the whole day without allowing them any social interaction. Horses are social herd animals and they NEED to be with other horses! In not allowing them to have any social interaction, the horse breeders are keeping them in a super-max prison and have warped their sexuality (i.e. turning them into aggressive sex maniacs)!

In a normal situation, a stallion that wants to mate with a mare has to ask her very nicely if he can mate with her, very much equivalent to a human dating situation. And is the mare refuses, there is nothing the stallion can do.

What happens normally! (http://cdn-write.demandstudios.com/upload//1000/200/60/6/11266.jpg)

However, these horse breeders in an attempt to protect their precious stallions, tie up the mare and hobble her feet (so she cannot kick the stallion if she does not like him) and then let the stallion loose. He then RAPES her. It is nauseating, disgusting and repulsive and insane that people are even able to think of doing it.

In another case in the book, Temple Grandin speaks of rapist-killer roosters. However, before you go into cardiac arrest over the world’s state of affairs, this is almost completely unintentional and came as a result of single-trait breeding. However, what was strange was that the owners of these chicken farms treated it as normal because it was so prevalent!

To mate, a normal rooster does a courtship dance which is hardwired into his brain or what we term fixed action pattern. This is turn generates a fixed action pattern in the hen, that is she goes into a crouching position (which is sexually receptive), to show the rooster that she too is ready to mate. “She doesn’t crouch down unless she sees the dance.”(p. 70)

The roosters that were breeded to be faster-growing, bigger-breasted, stronger AND with longevity however, did not have this courtship dance hardwired into their brains. Therefore the hens stop crouching down for them and these roosters turned into rapists! They pounced on the hens and tried to copulate with them by force and if the hens tried to run, the roosters would attack her with his toes and literally slash her to death.

Normal mating procedure: hen crouching down for the rooster (http://farm2.static.flickr.com/1196/929492735_e080b3d231.jpg?v=1209824151)

Of course the breeders did not breed for these rapist-killer roosters on purpose but in breeding through many generations for faster-growing, bigger-breasted, stronger AND with longevity roosters, it somehow screwed up the genes related to mating behaviour.

Apparently, this warped evolution happens often when breeders over-select for a particular trait. I guess we can’t always have our cake and eat it too.

References:

Grandin T. and Johnson C. (2005) Animals in Translation: Using the Mysteries of Autism to Decode Animal Behaviour.

Millman, S. T., Duncan I. J. and Widowski T. M. (2000) Male Broiler Fowl Display High Levels of Aggression Towards Females. Poultry Science 79: 1233-1241

http://linuxette.org/wp-content/uploads/2007/10/water_bear.jpg

If you own a water bear(Tardigrada), there’s plenty of things that you don’t have to worry about, like, whether it gets enough food, water, space to run about or whether can it withstand the warmth and humidity of Singapore. The largest of this tiny species, can grow to an impressive 1.5mm, but this little boy is tough. It can withstand temperatures of up to 151 °C and down below at –272 °C (that’s 1 °C above absolute zero). For the benefits of the many Arts student in this module, this is absolute zero. http://en.wikipedia.org/wiki/Absolute_zero

The water bear can also survive in vacuum in open space and solar radiation combined for at least 10 days!! Basically, you can just throw your water bear into space and it’ll probably be floating around leisurely, looking at all the different planets from a view that most of us will probably not get to see for the rest of our lives. The only two organism that can survive in that environment are namely lichens and bacteria, but who would want to keep a combination of fungus/algae and bacteria for pets?!?! The former are essentially plants, they don’t move and people will think that you are weird when they see you talking to one. Bacteria are worst pets, you can’t even see them!!!! This is why Water Bear beats bacteria and lichens as pets.

Water BEar

The reason that these feisty little creatures can survive in the hostile environments is due to their ability to reverse metabolism and enter in this state called cryptobiosis. Theoretically, once in cryptobiosis, a creature can survive indefinitely until conditions becomes more hospitable. A water bear can survive for more than a decade, even in a dehydrated state, in cryptobiosis. All the previous examples of the water bear surviving in extreme conditions are made possible by cryptobiosis. Although when exposed to UV radiation, they only managed to survive 30 minutes after being rehydrated, they died only after reproducing, ensuring that their genes are passed on.

After reading about water bears, I can’t help but think that these creatures, are perfectly suited for irresponsible pet owners! When they are interested in looking, talking or “playing” with the water bear, all they have to do is rehydrate them, and when they’ve lost interest, they won’t even need to abandon them anywhere!! All they have to do is to leave them alone, and they’ll enter cryptobiosis, awaiting for the next time their owners get interested again. This is a win-win situation for both irresponsible pet owners and SPCA who would not have to worry about taking in abandoned pets ever again!!

Reference

K. Ingemar Jönsson, Elke Rabbow, Ralph O. Schill, Mats Harms-Ringdahl and Petra Rettberg (2008).”Tardigrades survive exposure to space in low Earth orbit. Current Biology18 (17)

Bertolani, R. et al (2004). “Experiences with dormancy in tardigrades”. Journal of Limnology 63(Suppl 1): 16–25.

Tardigrade. Accessed on 13th April 2009. (http://en.wikipedia.org/wiki/Tardigrade)

Video taken from:

http://www.youtube.com/watch?v=Ho2sPvza0oA&feature=related

It’s that time of the year again, when the waters to the south of Singapore bristle with excitement and some hot, steamy action. A few days after the full moon in less than a weeks’ time, just after nightfall… the activities will begin. Hordes of fish will gather in frenzy because they can sense the upcoming action. While the corals prepare for a mass orgy, the fish prepare for a huge buffet. Soon the corals become swollen, and then pink bundles burst out from each of the coral polyps, releasing millions and millions of eggs and sperm into the water.

What’s going on? The corals do it. So do the giant clams, sponges and a whole lot of other marine organisms that are quite immobile as adults. Because they are immobile, these organisms exploit the aqueous environment that they live in to help them mate; They release their eggs and sperm into the water, a process termed broadcast spawning, which allows the eggs and sperm to fertilize externally and produce motile larvae for the propagation of the species. To view an awesome video clip of a spawning coral, please click on the link entitled “Coral Spawning” here.

For many species of the hard corals, synchronous mass spawning has been documented all over the world, with that from the Great Barrier Reef in Australia being one of the most well-documented, but this actually occurs in Singapore (Guest et al., 2002) too! Although we do not get thick mats of spawn slick here in Singapore, it is still one of the most breathtaking events on the reef here, THE annual mass spawning of corals, where multi-species of corals spawn in synchrony.

Now broadcast spawning allows for efficient mixing of the gene pool, but why would different species do it together?? The highly nutritious eggs attract hordes of fish that could easily deplete much of the coral babies. By producing an over-abundance of spawn at one go, the predators are overwhelmed, thereby increasing the chances of survival of each coral baby. Simply imagine you are at a buffet, with a great spread in front of you. No matter how delicious the food is, there is only so much that one can consume at a go! This spares the rest of the coral larvae (a.k.a. fish food), till they are ready to settle down and grow into an adult coral colony.

So if you decide to go swimming in the sea in the next few weeks, expect the water to be a little more turbid or have a different smell, and you might also see more schools of fish out in their feeding frenzy!

References
Guest, J.R., Baird, A.H., Goh, B.P.L. & Chou, L.M. 2002. Multispecific, synchronous coral spawning in Singapore. Coral Reefs, 21: 422-423.